The Best Aquarium Silicone for 2021


Sealing the tank’s edges using an effective sealant is a great move because it can ensure a long-lasting hold and performance. However, it is not easy to choose among the best aquarium silicone on the market. It is why it pays off to study your options well.

To choose the right one, you can check out the following guide. It features the top six silicone sealants on the market, each with pros, cons and special qualities. In addition, you’ll find a section on the factors to look into when comparing your choices. If you’re ready, let us begin and find the aquarium silicone that’s right for your needs.

What is the Best Aquarium Silicone for 2021

Top 6 Best Aquarium Silicone Reviews

1. Clear Aquarium Silicone Sealant


The Clear Aquarium Silicone Sealant is one of our top choices for an aquarium silicone that is easy to use and safe for your tank friends. In addition, you’ll appreciate that it can form a strong and cohesive bond to your tank without having to buy any primers. That is moneysaving and practical, one of the things that make for a good aquarium silicone.

It is also a good choice that stays sealing the glass tank without being affected by the water. It is unaffected by it once cured. It is non-slump sealant that you can also apply without sagging or flowing even applied on a vertical surface.

I would also like to mention that the ASI Aquarium Silicone Sealant could be applied even to varying surface temperatures up to 120 degrees Fahrenheit once cured.


  • 2-oz fluid
  • Bonds strongly
  • Does not require a primer
  • Non-slump sealant
  • Can be used to vertical surfaces without sagging or flowing


  • Glue smell even without opening

2. Gorilla Clear 100 Percent Silicone Sealant Caulk


The Gorilla Clear sealant or caulk is another top choice on the market because of its unique features. For one, it is mildew and mold resistant, which ensure of a long-lasting performance. It is also available in a large size of 10 ounces so that you can use it for a few applications.

In addition, the item is versatile to apply on many surfaces and can be used for applications, such as bath, kitchen, door and window. It can also dry translucent clear to prevent discoloration.

It is also good for sealing cracks and gaps between surfaces. You can also use it for marine and other applications indoors or outdoors. It is also 100% waterproof and won’t crack or shrink. It will not also turn yellow.


  • Waterproof for long-lasting performance
  • Mildew and mold resistant
  • Large 10-ounce cartridge
  • Versatile for a wide range of applications and surfaces
  • Doesn’t crack or shrink



  • Can seriously burn if applied without gear

3. 3M Marine Adhesive Sealant 5200 Black


The 3M Marine Adhesive Sealant is a decent choice on the market when comparing your options for an aquarium caulking or sealing product. This Adhesive Sealant 5200 is a high strength formula that can offer a lasting hold. It is also versatile for a wide range of applications including on boats, kitchens and many surfaces.

More so, it is a top-rated choice for permanent sealing or bonding of gel coat, fiberglass or wood. Once cured, it will form a waterproof and elastic seal on the boat hardware, joints, above/below the waterline and other surfaces.

It is also made of flexible and tough polyurethane polymer, which can form a sturdy bond. Finally, it is able to retain the bond even during swelling, vibration, shock or shrinking.


  • High strength and long lasting hold
  • Sticks well once cured
  • Waterproof seal
  • Rubbery and firm
  • Seals gaps and cracks effectively


  • Discoloration can be an issue

4. 3M Marine Adhesive Sealant 5200 Fast Cure


The 5200FC is another effective sealant for your tank because it can work fast and cure within 48 hours. You don’t also need mixing to use it and is easy to use. It is also one of the top picks among the experts because they just love the strong adhesive that it can bring. They can rely on its sturdiness above or below the waterline.

It is also a long-lasting formula, which is composed of polyurethane polymer that can resist saltwater and weathering. This item can also stay flexible and won’t peel or crack. It can deal even with structural movement, vibration or shock. Overall, it might be for you if you’re looking for a reliable and long-lasting sealant for your tank. Check it out now.


  • Can cure fast within 48 hours
  • Requires no mixing
  • Can retain strength above or below the waterline
  • Long-lasting formula
  • Can be used on boats and RVs


  • Can harden inside the tube

5. Permatex 80050 Clear RTV Silicone Adhesive Sealant


You should not miss the Permatex 80050 when comparing your options for a clear and effective aquarium sealant. It is also notable for being flexible and durable, offering a long-lasting hold. This item can also offer a waterproof performance to withstand even continuous immersion. It can also deliver a strong hold to keep up with shocks and vibrations.

The Silicone Adhesive Sealant is one of the most versatile choices around because it can be used as an indoor or outdoor sealant. It can be used in repairing, sealing, bonding, securing and mending metal, plastics, glass vinyl and fabric. It can also be used for vinyl tops and weather stripping. It is also useful for doorframes, roofs and seams.


  • Great for indoor or outdoor use
  • Durable and waterproof
  • General-purpose use
  • Can seal and mend metal, glass and other materials
  • Can keep up to 400 degrees Fahrenheit


  • Not for engine gasket, electrical connection applications and windshield installation

6. Clear 100% RTV Silicone Sealant


Do not miss the ASI silicone sealant when shopping around for a tank sealant. It already comes as a 10.2 ounces variety that makes it a good choice among those looking to use it for a wider surface area.

It is also versatile that it can be used in sealing truck trailers, sheet metal and cabins. You can also rely on it for general industrial applications and HVAC.

One of the things that make it unique is that it is weather resistant. You can rely on it when it comes to dealing with UV radiation and ozone. It can also withstand temperatures, airborne chemicals and freeze-thaw conditions. Check it out now if you’re looking to take advantage of these features.


  • No discoloration transparent color
  • 2 ounces and moneysaving
  • Weather resistant
  • Can be used on a wide range of surfaces
  • Can keep up with high temperatures up to 400 degrees Fahrenheit


  • Hardening on the tube can be an issue

Aquarium Silicone Buying Guide

It is uneasy to select an aquarium silicone that is best for your situation and needs because there is a wide selection of these products on the market now. The following are some of the things to remember when choosing among the available sealants.


One of the main qualities of a good sealant is its flexibility. It should be rubbery and versatile that it is easy to apply, too.

Trusted manufacturer

Another thing to check when comparing your options is its manufacturer. While you can find plenty of choices on the market, not all of them are from reliable and credible manufacturers. It is because the product must be safe for use in the aquarium. For this reason, you should buy only from a trusted source.

Sticking ability

In addition to the above, you should check as to how well the product sticks to the surface. It must be a good adhesive that can be applied even on a vertical surface. Once cured, it should be able to deal with the constant immersion to the water. You might want to get started in comparing different options using the reviews earlier.

Resistant to mold or mildew

Aside from those mentioned earlier, you must also pick a product that is resistant to mold and mildew. With these features, you can be certain that it can help you solve any issues of leaks in your tank while also not inviting the growth and development of mold/mildew.

Not discoloring

When shopping around for this item, you should opt for a sealant that does not fade or discolor. For the best results, you might want to pick a transparent or clear sealant.

There you have some of the main considerations to look into when comparing the different silicone sealants on the market. Be able to look into these features to ensure that you’re buying an effective sealant for your tank.

What is an Aquarium Silicone?


The silicone sealant is just like what its name suggests. It is a product especially designed and made to seal or caulk the tank to solve or prevent leaks. This silicone sealant has the ability of keeping up with changing temperatures and immersion to water. Nevertheless, it is a must-have for every hobbyist or fish tank enthusiast.

Types of Aquarium Silicone

On the market, you can find different types of aquarium silicone sealants to choose from and use. Generally, there are two types of sealants that can help caulk or seal the edges of your tank.

Natural silicone sealants

They are chosen for their special features, including not coming with a strong odor once cured. You can rely on it when sealing your tank and preventing or solving any leaks. They are with excellent adhesive properties and can be made of materials including PVC-U, aluminum, plastics, glass and stone. The downsides are that they can take a longer time to cure and are expensive. In addition, they can take days before curing based on factors like humidity, temperature and thickness.

All-purpose silicone

It is another type of sealant that is used to seal many types of surfaces that include wood and glass. It is a universal choice when deciding for a sealant. In addition, many of them are safe for tanks in addition to its better performance in terms of long-lasting strength and elasticity. The best ones also don’t have fungicides on them.

Nevertheless, you must pick an aquarium silicone that will not cause harm to your fish friends and the plants in the tank. Be able to think about those factors mentioned earlier so that you can make a better decision. You can also refer to the above buying guide to pick one among the top items in the category. They are safe, bond well, and can offer lasting sturdiness.

Why Do You Need Aquarium Silicone?

What are the benefits of using these silicone sealants? Check out the following for what to get when you use this product to seal the tank’s edges.


Good ones are also transparent to prevent discoloration. It can also ensure that it will not ruin the aesthetics of your tank. It is one of the reasons you need this sealant that can offer effective sealing while being transparent to ensure a good look of your tank.

Authenticity and safety

The best ones are made of authentic silicone, which can be used in all aquariums safely. But then, you have to be sure that you’re buying a safe to use sealant that will not harm your fish and the plants inside the tank.

Long lasting curing

In addition to safety, the right sealant can also offer a lasting strength and elasticity. It has a lasting curing that you can rely on for a long time. Get started by checking out those items featured above. They are by the most trusted brands that offer quality and long lasting performance.

Solid sealing

In addition to the above benefits, the right one can also offer solid sealing. It will not be affected by the constant water immersion and temperature changes.

Frequently Asked Questions


How to remove silicone from glass aquarium?

It is not hard to remove the silicone sealant at all. You just have to empty your tank and let it dry. Next, set your dryer to high heat so that it can warm the sealant. Stop heating it once you it started melting. Then, get a razor blade to scrape the sealant from the glass. Lastly, moisten a sponge to scrap off any remaining sealant.

This method is one of the easiest methods to remove the sealant from the tank. However, there can be some bits behind if you have much sealant to remove.

Is aquarium silicone safe for fish?

Yes, it is safe for the fish provided you buy a sealant that is graded and rated to seal the tank. Do not buy those silicone sealants that are not tested and proven safe for your tank and its content.

The difference between aquarium silicone vs regular silicone

This question is probably the next one you have in mind if you are deciding whether to buy a regular silicone or aquarium silicone. At the very least, you must find one that is food safe and 100 percent silicone.

Ensure that it will not leave any additives or fungicides in the tank. According to some sources, the difference is also based on the acid that it generates while it cures. And for many aquarium sealants, they are using acetic acid for curing, while the others a different curing method.

Where to buy Aquarium silicone?

There are many places to buy a tank silicone. For one, you can find them in fish supplies stores and pet supplies shops. You can choose from one of those safe for use in tanks and your fish. But if you’re looking for a wider range of selection and at varying prices, you might want to go to online marketplaces like


Choosing among the available best aquarium silicone on the market can be easier if you know how to compare the top picks as well as their features. You’ll also make a better decision with information on the things to look for when shopping around for this product.

When comparing your choices, make sure to check certain features including safety and ease of use. In addition, you might want to get started with the top picks on the market so that you can be sure that you’d use an effective sealant for your tank. Pick your aquarium silicone using the above reference today!

2 thoughts on “The Best Aquarium Silicone for 2021”

  1. Hi,
    I went to the store and they told me to use lwloctite waterproof sealant so I picked it up and used it to reseal a 36 gallon bowfront. Then afterwards, I read the fine print that says it’s not suitable for aquariums over 30 gals or a height of 18 inches or more. Do I have to redo the whole thing again with different sealant, or do you think it will be fine?


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